presented at the

1
THERMAL AND STRESS ANALYSIS OF A SOLID DT TEST
SPECIMEN
James K. Hoffer and J. Gregory Swadener

• presented at the
• Laser IFE Workshop
• sponsored by
• The Department of Energy Offices of Fusion
  Energy Sciences Defense Programs
• November 13, 2001

2
Target Injection-1 Target Materials Response -
LANL
Overall Objective. Response of target
materials to injection stresses FY 02
Deliverables.. 1. Modify existing apparatus to
accommodate new DT strain cell. 2. Assemble
and bench-test strain cell using no hydrogen
(warm experiments, using butter). 3. Start
experiments to measure DT yield strength
and modulus. PI Experience. Extensive
experience with DT and DT-layering (POC J.
Hoffer) Proposed FY02 Amount.. 200
k Relevance of Deliverables X
NIF Research in materials in NIF targets
Laser RR Facility. Other
DP/NNSA X Energy Needed for
injection into chamber Related DP
activities Define experiments to measure the
effect of a sudden thermal load on a
DT-layered target
3
Finally, we enclose all of this assembly inside
a tritium cell with optical ports
4
What the camera might see(version A)
5
What the camera might see(version B)
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What the camera might see(version C)
7
Whats next?

• Complete design of the DT-strain cell
• Perform thermal modeling of layer formation
• Perform strain analysis on proposed sample shape
• Redesign cryostat if necessary
• this assembly may be too long for existing
  apparatus

8
In fact, the DT-strain cell is not too large,
but the optics dont fit our existing cryostat

• existing cold can in optical cryostat
• DT-strain cell
• Existing cold plate
• Closed cycle helium refrigerator second stage
  (1020 K) plate

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THERMAL STRESS ANALYSES
TYPICAL SPECIMEN SHAPE
THERMAL EQUILIBRIUM SHAPE?
10
Hydrogenic solid shear strength datafrom ORNL H,
D, T pellet experiments
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MATERIAL PROPERTIES AT 18 K
estimate
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THERMAL ANALYSIS FE MESH
200 mm
1.0 mm
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THERMAL ANALYSIS ITERATIVE SOLUTION
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THERMAL ANALYSIS NOTCH DEVELOPS
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THERMAL ANALYSIS 110 mm layer
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THERMAL ANALYSIS DETAIL
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D2 Stress-Strain Response Bolshutkin et al., 1970
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STRESS ANALYSIS REFINED MESH
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ELASTIC STRAINS e 0.0005
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ONSET OF YIELDING e 0.001
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ADDITIONAL YIELDING e 0.0015
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WORK HARDENING e 0.003
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ADDITIONAL HARDENING e 0.004
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ADDITIONAL HARDENING e 0.006
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HIGH STRESS e 0.009
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FEA LOAD-DISPLACEMENT RESULTS
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THERMAL STRESS ANALYSES
TYPICAL SPECIMEN SHAPE
THERMAL EQUILIBRIUM SHAPE?